The Science of Gore's Nobel

Holman W. Jenkins

What if everyone believes in global warmism only because everyone believes in global warmism?

The Nobel Committee might as well have called it Al Gore's Inner Peace Prize, given the way it seems designed to help him disown his lifelong ambition to become president in favor of a higher calling, as savior of a planet.

The media will be tempted to blur the fact that his medal, which Mr. Gore will collect on Monday in Oslo, isn't for "science." In fact, a Nobel has never been awarded for the science of global warming. Even Svante Arrhenius, who first described the "greenhouse" effect, won his for something else in 1903. Yet now one has been awarded for promoting belief in manmade global warming as a crisis.

How this honor has befallen the former Veep could perhaps be explained by another Nobel, awarded in 2002 to Daniel Kahneman for work he and the late Amos Tversky did on "availability bias," roughly the human propensity to judge the validity of a proposition by how easily it comes to mind.

Their insight has been fruitful and multiplied: "Availability cascade" has been coined for the way a proposition can become irresistible simply by the media repeating it; "informational cascade" for the tendency to replace our beliefs with the crowd's beliefs; and "reputational cascade" for the rational incentive to do so.

Mr. Gore clearly understands the game he's playing, judging by his resort to such nondispositive arguments as: "The people who dispute the international consensus on global warming are in the same category now with the people who think the moon landing was staged in a movie lot in Arizona."

Here's exactly the problem that availability cascades pose: What if the heads being counted to certify an alleged "consensus" arrived at their positions by counting heads?